Cryostat quick freeze stages and attachments therefor



Oct. 5, 1965 N. J. zEYTooNlAN CRYOSTAT QUICK FREEZE STAGES AND ATTACHMENTS THEREFOR Filed Sept. 23, 1965 /7 Vi* I Il?. E

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United States Patent O 3,209,82l QRYUTAT @HECK FREEZE STAGES AND ATTACHMENT?? 'EHEREFR Nerses d. Zeytoontan, Waltham, Mass., assignor to linternationall Equipment Co., a corporation of Massachusetts Filed Sept'. 23, i963, Ser. No. 310,576 6 laims. (Ci. 165-lt85) The present invention relates to cryostat quick-freeze stages and to `attachments therefor.

in the preparation of tissues for various diagnostic procedures, fresh tissue is placed in specimen holders and frozen. The specimen holder is then transferred to a microtome by which the frozen tissue is cut into the thin sections required for such procedures. A cryostat has a cold chamber in which the microto-me is located but, as it is desirable to have the fresh tissue quickly frozen, it is a common practice to provide the cryostat with a quick-freeze stage also mounted within the cold chamber but with its temperature separately controlled. Such a stage is designed to receive several holders which are commonly discs each having a grooved, tissue-receiving face and a stern extending from its undersurface which is otherwise liat, the stage having stem-receiving bores permitting the undersurface of the holders to rest thereon.

The objective of the present invention is to ensure the maximum effectiveness of the quick-freeze stage and this is accomplished by providing it with at least one chilled cover for the tissue holding face of a specimen holder and also operable both to shield the tissue from the `ambient air and to maintain the undersurface of the covered holder in good thermal contact with the quickfreeze stage,

Such means may comprise a vertical post carried by the cryostat quick-freeze stage and provided with an arm pivoted to swing in a horizontal plane from a position over the stage into a position away therefrom. The post may be detachable from the stage or it may be a permanent part thereof. A horizontal bar has a stern rotatably connected to the arm for limited vertical movement relative thereto and discs are supported below the bar for limited vertical movement relative thereto, the discs being spaced from each other so that each may rest on a different specimen holder carried by the stage. The range of relative movement between the discs and the bar from which they depend and between the bar and the arm is such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position, the discs are seated on a stage or on a holder thereon and are independent of each other, the arm, and the bar as far as vertical movements are concerned.

As the discs are relatively heavy and are of material that is a good heat conductor, they have the important function of providing a cover for the holders and of ensuring good thermal contact between the holders and the stage. As the discs are preferably resting on the stage until used, they are so chilled as to assist materially in the quick freezing of the tissue when applied, as covers, to the specimen holders.

In the accompanying drawings, there is shown an embodiment of the invention illustrating these and other of its objectives as well as its novel features and advantages.

ln the drawings:

FlGURE l is a top plan view of an attachment in accordance with the invention clamped to the quick-freeze state of cryostat,

FGURE 2 is a front view thereof, and

FIGURE 3 is an end view thereof.

A stage 5 is shown as mounted on the wall 6 of the cold chamber of a cryostat and as having a row of four vertical bores 7 each adapted to receive the stem 8 of a specimen holder 9 and as having receivers it) dimensioned to receive the holder 9. As may be seen in FIGURE l, the upper or tissue-receiving face of the holder 9 has concentric grooves 9A and, as shown in FIGURES 2 and 3, the undersurface 9B of the holders is at and rests on the bottom of the receivers lil. Such stages are refrigerated but as the means for so doing are conventional, they are not shown but it is noted that the temperature of the stage is substantially lower than the temperature established for the cold chamber.

A vertical post il. has a fixed jaw l2 in engagement with the upper surface of the stage 5 midway between its ends and a lower jaw ll?) adapted to be brought into clamping engagement with the undersurface thereof by means of the cap M threaded on the lower end of the post lit. The upper end of the post il has a shoulder i5 providing pivotable support for one end of a horizontal arm to which is held in place on the post di. as by the screw t7. The portion 11A of the post l1 between the iixture 12 and the lower jaw 13 is rectangular in cross section and the lower jaw 13 has. an upwardly disposed lip MA engaging the lower part of the post portion HA thereby to be held against rotation.

The vertically disposed stem lit of a horizontal bar l@ extends upwardly through the other end of the arm 16 and is both slidable and rotatable relative thereto. At `its upper end, the stem lit has a knob 20 and is suiciently long so that the bar i9 may be moved vertically a predetermined distance between a lower position in which the knob 2@ rests on the upper surface of the arm llo and an upper position in which the bar 19 engages the undersurface thereof.

Two discs 2t are shown. Each disc 2l is of stock that is a good heat conductor, copper for example, and has a stem 212 with each stem 22 extending slidably through an appropriate end of the bar 1&9 with retaining nuts 23 threaded on their upper ends. The discs 2i are so dimensioned that they function as covers for the specimen holders 9 and are relatively heavy. The distance between the centers of the discs 2l is the same as the distance between the bores 7 of the stage 5.

lt will be appreciated that the ranges of relative movement between the discs 2l and the bar 19 and between the bar 19 and the arm le are such that in the upper position of the bar 19, the discs 2l are held above the stage 5 and the holders 9 so that the arm le may be swung away from the stage 5 to permit specimen holders to be removed or swung over the stage 5 with the bar 19 then positioned so that the two discs 2i overlie the two specimen holders 9 at yone end or the other of the stage. ln the lower position of the bar t9, the discs 21 seat on the stage 5 or on a holder 9 thereon and are free, in relation to the vertical, with respect to the bar, the arm, and one another.

In practice, the discs 2li rest on the stage 5 and hence are chilled. When specimen holders 9 are mounted on the stage 5, the discs are placed thereon to cover the tissue samples to be frozen and, because of their low temperature, each disc contributes to the quick freezing of the samples because of this fact and because its weight ensures that the undersurface of each specimen holder 9 is in good thermal contact with the stage 5.

I claim:

ll. An attachment for a cryostat stage having a row of stations to receive specimen holders during the freezing of specimens, a vertical post attached to said stage, an arm pivotally connected to said post to swing in a horizontal plane from a position over said stage into a position away therefrom, a horizontal bar rotatably and slid- 3 ably connected to said arm for vertical movement relative thereto between upper and lower positions, a series of discs, and means connecting each disc to said bar for limited vertical movement relative thereto, said connecting means being so spaced that the clics may each rest at, a station, if no holder is positioned at that station, otherwise on such a holder, the range ot relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position of the bar, the discs are free with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

2. An attachment for a cryostat stage having a row of stations to receive specimen holders during the freezing of specimens, a vertical post attached to said stage, an arm pivotally connected to said post to swing in a horizontal plane from a position over said stage into a position away therefrom, a horizontal bar rotatably and slidably connected to said arm for vertical movement relative thereto between upper and lower positions, a pair of discs, one for each end of said bar and connected thereto for limited vertical movement relative thereto, said limited relative movements being such that the discs may each rest at a station, if no holder is positioned at that station, otherwise on such a holder, the range of relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position of the bar, the discs are free with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

3, An attachment for a cryostat stage having a row of stations to receive specimen holders during the freezing of specimens, a vertical post attached to said stage, an arm connected to said post, a horizontal bar rotatably and slidably connected to said arm for vertical movement relative thereto between upper and lower positions, a series of discs, and means connecting each disc to said bar for limited vertical movement relative thereto, said connecting means being so spaced that the discs may rest at a station, if no holder is positioned at that station, otherwise on such a holder, the range of relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position of the bar, the discs are tree with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

4. ln a cryostat, a quick-freeze stage having a row of stations to receive specimen holders during the freezing of specimens, a post, an arm pivotally connected to said post to swing in a horizontal plane from a position over said stage into a position away therefrom, a horizontal bar rotatably and slidably connected to said arm for vertical movement relative thereto between upper and lower positions, a series of discs, and means connecting each disc to said bar for limited vertical movement relative thereto, said connecting means being so spaced that the discs may each rest at a station, if no holder is positioned at that station, otherwise on such a holder, the range of relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position of the bar, the discs are free with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

5. In a cryostat, a quick-freeze stage having a row of four stations to receive specimen holders during the freezing or" specimens, a post located between the second and third station, an arm pivotally connected to said post to swing in a horizontal plane from a position over said stage into a position away therefrom, a horizontal bar rotatably and slidably connected to said arm for vertical movement relative thereto between upper and lower positions, a pair of discs each connected to one end of said bar for limited vertical movement relative thereto, said limited relative movements being such that the discs may each rest at a station, if no holder is positioned at that station, otherwise on such a holder, the range of relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position of the bar, the discs are free with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

d. In a cryostat, a quick-freeze stage having a row of stations to receive specimen holders during the freezing of specimens, a post, an arm pivotally connected to said post and extending over said stage, a horizontal bar connected to said arm for vertical movement relative thereto between upper and lower positions, a series of discs, and means connecting each disc to said bar for limited vertical movement relative thereto, said connecting means being so spaced that the discs may each rest at a station, if no holder is positioned at that station, otherwise on such a holder, the range of relative movement between the discs and the bar and between the bar and the arm being such that, in the upper position of the bar, the discs are held above the stage and any holder thereon and, in the lower position ot the bar, the discs are free with respect to said bar, arm, and one another to move vertically downwardly to seat at a station unless a holder is positioned at that station, otherwise to seat on such a holder.

References Qited by the Examiner UNITED STATES PATENTS ROBERT A. OLEARY, Pil'nmry Examiner. 

4. IN A CRYOSTAT, A QUICK-FREEZE STAGE HAVING A ROW OF STATIONS TO RECEIVE SPECIMEN HOLDERS DURING THE FREEZING OF SPECIMENS, A POST, AN ARM PIVOTALLY CONNECTED TO SAID POST TO SWING IN A HORIZONTAL PLANE FROM A POSITION OVER SAID STAGE INTO A POSITION AWAY THEREFROM, A HORIZONTAL BAR ROTATABLY AND SLIDABLY CONNECTED TO SAID ARM FOR VERTICAL MOVEMENT RELATIVE THERETO BETWEEN UPPER AND LOWER POSITIONS, A SERIES OF DISCS, AND MEANS CONNECTING EACH DISC TO SAID BAR FOR LIMITED VERTICAL MOVEMENT RELATIVE THERETO, SAID CONNECTING MEANS BEING SO SPACED THAT THE DISCS MAY EACH REST AT A STATION, IF NO HOLDER IS POSITIONED AT THAT STATION, OTHERWISE ON SUCH A HOLDER, THE RANGE OF RELATIVE MOVEMENT BETWEEN THE DISCS AND THE BAR AND BETWEEN THE BAR AND THE ARM BEING SUCH THAT, IN THE UPPER POSITION OF THE BAR, THE DISCS ARE HELD ABOVE THE STAGE AND ANY HOLDER THEREON AND, IN THE LOWER POSITION OF THE BAR, THE DISCS ARE FREE WITH RESPECT TO SAID BAR, ARM, AND ONE ANOTHER TO MOVE VERTICALLY DOWNWARDLY TO SEAT AT A STATION UNLESS A HOLDER IS POSITIONED AT THAT STATION, OTHERWISE TO SEAT ON SUCH A HOLDER. 